Paracortina voluta Wang & Zhang, 1993

Figs 20, 21, 22, 27C, D, 28

Paracortina voluta Wang & Zhang, 1993: 377, figs 6-9; Stoev and Geoffroy 2004: 103, key; Liu and Tian 2015: 139, key.

Studied material.

2 males, 1 female, China, Sichuan Province, NW Pingchuan, 27°40'07"N, 101°44'04"E, 18.07.2011, I. Belousov & I. Kabak leg. (Rd 5346 ZMUM), Akkari det. 2023.

Diagnosis.

Most similar to P. viriosa in the shape of the distal part of the telopodite with two main folds and a strong hook-shaped median processes, differing in the earlobe-shaped distal process and the smaller and more distally located anterior lamella.

Descriptive notes.

Male with 56PTs+Telson. Length ca 49.5 mm. Live colour unknown. Preserved specimen with a brownish general colour, legs and antennae dark brown (Figs 20, 21A), Head with dark pigmentation on the vertex and frons (Fig. 20B, C), mandibular stipes and gnathochilarium with yellowish spots. Fields of ommatidia subtriangular, composed of ~ 47 ommatidia in ten rows (Fig. 20B, C). Organ of Tömösváry very large, ~ 1.2 mm, situated close to and touching anterior side of eye (Fig. 20B). Prozona brownish sputtered with a paler colour; metazona dorsally dark tawny-brown, especially on crests, anterior part pale with brown alveolate spots (Fig. 20A, B).

Male sexual characters.

Head with a protruding triangular projection on vertex (Fig. 20B, C, 21A). Leg-pairs 1 and 2 reduced and more setose than the rest, showing prefemoral and tarsal brushes, leg-pair 2 with a large anterior process on coxa and posterior gonopore (Fig. 21A), leg-pair 4 with anterior triangular projection on coxa (Fig. 21A), leg-pair 6 with one short triangular mesal process and a smaller lateral one on coxa, prefemur proximally slightly constricted on the posterior margin (Fig. 27C), leg-pair 7 with one mesal hyaline pointed process and a rounded projection surmounted by a similar but slightly smaller one, trochanter with a tuft of strong setae (Fig. 27D).

Gonopods. Parallel, slightly converging with the distal solenomeral processes of telopodites crossing (Fig. 21B-D). Each gonopod with two asymmetrical, short, clavate prefemoroidal processes with (pf1) broader and more setose than (pf2) (Figs 21B, C, 22); coxal anterior lobe lower than the lateral lobes low (Fig. 21C), long and falcate coxal process (b) reaching the distal part of the telopodite and apically pointed (Figs 21C, 22A, B, D). Telopodite (T) with a long stem, distally expanding in an earlobe shape with rounded lateral margin seen in posterior view (Fig. 21C, D), in anterior view as an oblique subtrapezoidal plate (Fig. 21B), with a transparent lamella (dl) attached on the lower part, marking and S-shape and serrated on the lower margin (Fig. 21B), mesal process curved upward, twisted and narrowing towards its apex (Figs 21B-D, 22A, B), bifurcating into the opening of the solenomere (s) and parasolenomere (ps).

Distribution.

This species was originally described from Ya Jang (= Jajiang) County, Sichuan, China. Here we add a new record from Yanyuan County which is ~ 250 km away in a straight line from the type locality (Fig. 28).

Comments.

Although we have no doubt about the identity of the studied specimens, when comparing the gonopod of the new material in mesal view (Fig. 20D) with the drawing provided in the original description of P. voluta (Wang & Zhang, 1993: fig. 6), we noticed a few differences in the shape of the distal process of the telopodite, with the mesal process more twisted and curved, the anterior lamella more serrated and turned downwards, and the “s-twist” more obvious in our specimen (visualised with a rounded notch in mesal view).

Both available identification keys for the family Paracortinidae (Stoev and Geoffroy 2004; Liu and Tian 2015) mention eight or nine “macrosetae” on the small prefemoroidal process and use this character to separate the species from its congener P. leptoclada . However, in the specimens we examined, this number greatly exceeds that (see Figs 21, 22), proving that this character is not reliable for species discrimination.